Noise reduction apparatus

ABSTRACT

AN ELONGATED, RECTANGULAR BAFFLE LOCATED IN THE CROSSOVER PIPE OF THE MULTI-STAGE COMPRESSOR OF WATER CHILLER APPARATUS.

2 Sheets-Sheet l INVENTOR.

T. H. BROCKIE NOISE REDUCTION APPARATUS O OO July 11, 1912 Filed Dec. 2, 1970 July 11, 1972 T. H. BROCKIE 3,676,012

NOISE REDUCTION APPARATUS Filed Dec. 2, 1970 2 Sheets-Sheet 2 INVENTOR. 7%477/45 /7. Z702Le BY mq w,

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United States Patent Olfice U.S. Cl. 415119 9 Claims ABSTRACT OF THE DISCLOSURE An elongated, rectangular bafile located in the crossover pipe of the multi-stage compressor of water chiller apparatus.

BACKGROUND OF THE INVENTION This invention relates to apparatus for reducing the noise often resulting from the operation of relatively large refrigeration apparatus, and more particularly to apparatus for reducing the noise of multi-stage rotary compressors.

Several methods have been attempted to reduce the sound level of multi-stage centrifugal compressors of the type used in large water chillers, for example. Sound reduction methods including compressor cut-off modifications have been attempted. Bafiles have also been employed in various types of refrigeration equipment for reducing the noise of such equipment. The noise carrying components have also been covered with acoustic attenuation material.

The present invention is of the baflie type and eliminates some of the objections to the other types of noise attenuation devices.

BRIEF SUMMARY OF THE INVENTION Briefly, this invention comprises an elongated, expanded metal bafile placed in the straight section of a crossover pipe of the two-stage compressor of a water chiller apparatus.

One of the primary objects of this invention is to provide a device which significantly reduces the noise produced by a multi-stage compressor.

Another object of this invention is to provide a device of the class described which may be easily installed in the crossover pipe of a multi-stage refrigerant compressor.

A further object of this invention is to provide a device of the type described which is adapted to absorb the acoustical energy in a crossover pipe with a metal baffle arrangement.

Another object of this invention is to provide a device of the type described which is economical in construction and eflicient in operation.

Other objects and advantages will be made apparent as the description progresses.

BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings, in which one of various possible embodiments of this invention are illustrated.

FIG. 1 is a front elevation of a water chiller employing a device of this invention;

FIG. 2 is an enlarged fragmentary view of FIG. 1;

FIG. 3 is an enlarged section taken along lines 33 of FIG. 2;

FIG. 4 is a plan view of the baffie device shown in FIG. 3, certain parts being removed and shown in section for clarity;

FIG. 5 is an enlarged fragmentary view of FIG. 3;

FIG. 6 is an enlarged fragmentary view of FIG. 4; and

FIG. 7 is an enlarged fragmentary side view of FIG. 5, certain parts being broken away for clarity.

3,676,012 Patented July 11, 1972 Like parts are shown by corresponding reference characters throughout the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and FIG. 1 in particular, a water chilling apparatus employing a device of this invention is generally indicated at 1. The chiller device 1 includes a two-stage compressor 3, the stages 5 and 7 of which are connected together by a crossover pipe '9, a cooler 11 and a condenser 13'. A control device 15 is also provided for the chiller device. As will be understood the crossover pipe 9 provides the means by which the refrigerant is delivered from the first stage 5 to the second stage 7' of the multi-stage compressor.

The sound baflle or attenuation device 17 of this invention is installed in a straight portion 19' of the crossover pipe 9. As shown in FIG. 2 the baffle 17 extends for a substantial portion of the length of the straight portion 19 of the crossover pipe. The bafile 17 is located in two generally U-shaped channel members 21 and 23 secured respectively to the upper portion and lower portion of the straight section 19 of the crossover pipe. The channels 21 and 23 are located to one side of the certical center line of the crossover straight section 19 for purposes to be described hereinafter.

The baffle 17 includes a plurality of sheets of expanded metal 25, such as aluminum for example, the ends of which are crimped together as indicated at 27. The bafile is generally rectangular in shape and the openings in the expanded sheets of aluminum are shown to be generally diamond-shaped. However, it will be understood that other shapes could be utilized without departing from the spirit of this invention.

The expanded metal is held in position by two metal sheets 29 and 31 located on opposite sides of the expanded metal filler material. The sheets 29 and 31 have a plurality of openings 33 therein, the particular openings shown being in the form of circular openings. The sheets 29 and 31 are folded around and upon one another at the ends thereof as shown at 35 and 37 in FIGS. 4 and 6.

It has been found that the acoustic energy of the chiller has been significantly reduced by placing an expanded aluminum baffle having retaining plates 29 and 3-1 located thereon in the crossover pipe. This reduction is due, in part, to the fact that the expanded aluminum bafiie extends throughout substantially the entire length of the straight secion 19 of the crossover pipe. The bafile is located to one side ofthe center line to minimize the possibility of creating noise due to the crossover pipe driving or moving the baffle. If the baffle were located on the center line the vibrating action of the section 19 might cause the bafile to be vibrated in a similar manner. It is also possible that the offset location of the bafile increases the frequency range in which the baffle tends to attenuate since the distance at any point from one side of the baffle to the outer wall is different than the distance from the other side of the battle to its outer wall.

In view of the foregoing it will be seen that the several objects of this invention are achieved.

Although only one embodiment of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible.

I claim:

1. In a centrifugal water chiller device having a multistage compressor, two stages of which are connected by a crossover pipe, a noise attenuating device comprising a baffle, said baflle extending axially of a portion of said crossover pipe, means mounting said bafile in said crossover pipe, said bafile comprising a plurality of sheets of expanded metal.

2. In a centrifugal water chiller device as set forth in claim 1 wherein said bafile further comprises retainer members on opposite sides of said sheets of expanded metal.

-3. In a centrifugal water chiller device as set forth in claim 2 wherein said retainer members have a plurality of closely spaced openings therein.

4. In a centrifugal water chiller device as set forth in claim 3 wherein said means for mounting said bafiie comprises a pair of generally U-shaped channels connected to said crossover pipe.

5. In a centrifugal water chiller device having a multi-stage compressor, two stages of which are connected by a crossover pipe, a noise attenuating device comprising a bafile, said bafile extending axially of a portion of said crossover pipe, means mounting said baffle in said crossover pipe, said baflle being offset to one side from a plane passing through and along the axis of said crossover pipe.

6. In a centrifugal water chiller device as set forth in claim 5 wherein said bafile comprises a plurality of sheets of expanded metal, the edge portions of said sheets of expanded metal being pressed together.

7. In a centrifugal water chiller device as set forth in claim 6 wherein said baffle further comprises retainer members on opposite sides of said sheets of expanded metal.

8. In a centrifugal water chiller device as set forth in claim 7 wherein said retainer members have a plurality of closely spaced openings therein.

9. Ina centrifugal water chiller device as set forth in claim 8 wherein said means for mounting said baflle comprises a pair of generally U-shaped channels connected to said crossover pipe.

References Cited UNITED STATES PATENTS 1,476,776 12/1923 Stamm et a1 415-119 2,731,194 1/1956 Kent 415-119 3,077,731 1/1963 Addie et a1. 415-119 3,375,970 4/ 1968 Zoehfeld 415-119 3,462,949 8/ 1969 Anderson et al 417-312 FOREIGN PATENTS 971,515 7/1950 France 415-119 HENRY F. RADUAZO, Primary Examiner U.S. Cl. X.R. 

